Technical Information

Building Digital Collections: A Technical Overview

The American Memory historical collections at the Library of Congress are
the product of a permanent commitment to explore and establish the best practices
of digitization, online presentation and access, and digital preservation of
historical materials. The information on this page documents current solutions
to technical challenges and solutions devised and implemented in the past.
The page is updated and expanded periodically.

Copyright

Information about copyright, privacy and publicity rights regarding the Library of Congress collections can be found on the Library's Legal Notices page.

Metadata

The Library of Congress' commitment to digitizing historical materials and making them broadly accessible led to an early and persistent concern with establishing versatile and flexible metadata protocols. The documents below explore some of our recent experiences.

Preservation

The American Memory raises preservation challenges on two fronts: preserving
original Library items fully and accurately in digital form; and designing
this vast treasury of digital objects so that their utility and accessibility
survive and flourish beyond the inevitably limited lifespan of any single technological
platform. The links below offer examples of how the Library is meeting these
challenges.

Scanning and Conversion

Digitizing priceless historical materials poses a unique challenge. Thus
American Memory demands continuous and resourceful attention to evolving
standards and practices in scanning and other methods of digital conversion.
The documents below reflect some of the most authoritative and pertinent of
these efforts; other information is linked under Background Papers in the next
section.

(Current documentation)
The Library of Congress is participating in the Federal Agencies Digitization Guidelines Initiative (FADGI), a collaborative effort by federal agencies formed in 2007 to define common guidelines, methods, and practices to digitize historical content in a sustainable manner. Within this, there are two separate working groups, Still Image and Audio Visual, with documentation specific to these areas.

Illustrated Book Study: Digital Conversion Requirements of Printed Illustrations.(View HTML or PDF version.)
By Anne R. Kenney and Louis H. Sharpe II with Barbara Berger, Rick Crowhurst,
D. Michael Ott, and Allen Quirk. Report prepared for the Library of Congress
by The Cornell University Library Department of Preservation and Conservation
and Picture Elements, Incorporated, to determine the best means for digitizing
the vast array of illustrations used in 19th and early 20th century commercial
publications.(July 1999)

Final Report of the Library of Congress Manuscript Digitization Demonstration
Project. (View HTML or PDF version.)
Includes copies of sample images created during two phases investigation of
best practices for digitizing manuscript documents. Sponsored by the Library
of Congress Preservation Office in cooperation with the National Digital Library
Program. (October 1998)

Text Mark-Up

American Memory
DTD for Historical Documents. The text of digital reproductions in American
Memory is almost always marked up in SGML using a TEI-conformant DTD. The same
DTD is used whether the text is generated by human transcription or optical character
recognition (OCR). [3 documents] (June 1998)

EAD Finding Aids. Links
to archival finding aids available online at the Library of Congress. Several
of the American Memory collections have associated archival finding aids. These
finding aids have usually been developed to guide users of the physical collection,
organized into boxes and folders. The finding aids have been marked up in XML following
the Encoded Archival Description (EAD)
standard. They may be viewed as framed and unframed HTML and printed as PDF; the HTML and PDF versions are generated from the EAD XML. (January 2006)

Background Papers

The following documents include some of the most significant materials from the early technical history of the American Memory Web site.

Turning
Pages within a Digital Reproduction. One example of a solution to a
problem found in many digitization projects -- how to present a sequence
of images considered a single item from a bibliographic viewpoint. (May
1998)